Echolocation signals of the plecotine bat, Plecotus macrobullaris Kuzyakin, 1965

Abstract

Plecotus macrobullaris was recorded in an alpine region in Switzerland. Like other species of the genus Plecotus, P. macrobullaris emitted multiharmonic, downward frequency-modulated signals consisting mostly of the 1st and the lower part of the 2nd harmonic. Signal structure depended on the distance to the background. The shortest signals (0.8 ms) were recorded close to the background. The first harmonic began at about 46 kHz and ended around 23 kHz. Signals were emitted in groups. The longest signals (up to 7.3 ms) were recorded above a meadow, far from background targets. These signals, which were more shallowly modulated, started at about 42 kHz and ended around 15 kHz. They occasionally lacked the 2nd harmonic and were often emitted only every 2nd or 3rd wing beat cycle. In short signals of up to 4 ms, the 1st and 2nd harmonic did not overlap, whereas overlap was prominent in longer signals. Although P. macrobullaris is genetically more closely related to P. auritus, its signal structure is closer to that of P. austriacus. Taking further evidence from morphological data, signal structure, and flight behaviour into account, we conclude that P. macrobullaris occupies a similar niche in mountainous areas as P. austriacus does in the lowland.